Ventilation of dynamoelectric machines



Aug. 6, 1940. H. E. sToKEs VENTILATION 0F DYNAMOELECTRIC MACHINES Filed May 26, 1958 lNvENToR Haro/dE SiO/Q65.

BY I l ATTORNEY UNITED STATES PATENT OFFICE VENTILATION OF DYNAMOELECTRIC MACHINE S Harold E. Stokes, Murraysville, Pa., assignor to Westinghouse Electric & Manufacturing Coinpany, East Pittsburgh, Pa., a corporation of Pennsylvania Application May 26, 1938, Serial No. 210,181

6 Claims. (Ol. 1'71-252) The present invention relates to the ventilation fOr each unit is also keyed to or otherwise mounted of dynamoelectric machines, and, more particun the Shaft. larly, to improved means for the ventilation of TO provide for ventilation of the machine, the double-armature machines of relatively large size. Space between the two units is completely en- In the past, the usual method of Ventilating Closed by a cylindrical cover 8 of sheet steel or 5 dynamoebgctrio machines has been 1-,0 pass cool other suitable material which is secured to the air through the machines, either directly from the inner sides 0f the stator frames I. This cover room in which the machines are located, or from may, if desired, be mede in WO Semi-Cylindreel Y ducts, and to discharge the heated air from the halves or other convenient subdivision and bolted t lOmaohines back into the room. In large motor together for ease in assembly. TWO large Open- 10'A rooms, however, Such as are found in modem ings 9 and It) are formed in this cover and are Steel minsI for example in which motors or genpreferably, although not necessarily, located diaerators aggregating many thousands of horsemetrically opposite to each other at the top and power may be infstauodV this method of ventilobottom of the machine. An air inlet duct II is tion results in excessively high temperatures in Secured 1 n th? Openmg 9 and extends th'Ough 15 the motor room. This gives Very undesirable the opening into the interior of the space enworking conditions and impairs the effectiveness d osed by-the C0Ver-8 AS Shown more Clearly in of the Ventilation Fig. this duct I is rectangular in cross-section The more modem practice, therefore is to and is closed at itslower end. Large circular 2o pass cool air from the room through the machines Opemngs I2 an? provlded on each 51de of the duct 20 and discharge the heated air outside of the motor Spd these openmgs are approxlmatly of the same room Where it is Cooled and Cleaned The C001 diameter as the armatures d. It will be seen from Fig. 1 that the duct is placed in the cover so air is then blown back into the motor room where e it is maintained at a pressure Slightly above that the opening.J I2 are concentric with the shaft atmospheric so that it will readily ow into and thlleiluglclfacghrrs 25 through the machines. ture The Object of the present invention is to pro s. An external air duct I3 is connected to the o enin It and as e h vide a double-armature dynamoelectric machine te or M or all ssolsnljttgrtCgnflrg which is adapted for vent1lation 1n accordance to conduct away the heated an, discharged from 30 with the method outlined above.

the machine. A further ObJect 1S to provlde a Ventllatnfg SYS' End bells I5 are secured to the outer sides of tem for a double'arma'ture dynamoelectrlc ma" the stator members I. These end bells have cenchine in which the cooling air' is taken from the tral openings of slightly greater diameter than room m Whch the mac-hm@ 1S located and the the armatures in order to permit the entrance of 35 heated air is schafged Outside 0f the roomsufcient air to cool the eld coils. Suitable brush The invention Wlll be mOie fiilly u ldel'stood rigging I6 is supported from these end bells. f1" om the accompanymg dmv/mg m Whlch In operation, as explained above, the air in the Figure 1 is a longitudinal s ecton through a motor room is maintained at a pressure slightly 40 d0ub1e*armat11e dynamoelect'lc mach-lne; and, above atmospheric and will therefore ilow throughv Fig. 2 is a perspective View 0f en air inlet duCtthe duct II and the openings of the end bells I5 40 The invention is shown in the drawing as apinto the machine. The major portion of the air plied t0 a dellbie-ermeiure direC Current menecessary to cool the machine enters through the chine, which may be either a motor or a genduct II and the openings I2 and passes through erator. As shown in Fig. l, this machine comthe radial ducts in the armature cores 4 and also 45 prises two units, each of which has a stator frame over and around the windings 5 as shown by the I on which are mounted a plurality of pole pieces arrows in Fig. l. A certain amount of air will 2 carrying eld windings 3. The armature or also flow into the machine through the end bells rotor member 4 of each unit consists of a lami- I5 past the brush rigging I@ and pass over the nated core having radial and axial air ducts and windings on the stator member to cool them. 50 carrying suitable windings 5 placed in slots about The openings in the end bells are so proportioned its periphery. The armatures of both units are that only enough air will flow through them to keyed, or otherwise secured to a common shaft provide the necessary ventilation for the field 6 which is supported for rotation in suitable exwindings. The heated air flows to the lower part ternal bearings, not shown. A commutator 'I of the machine and escapes through the duct I3 55 4members and havin-g two openings therein, an.

from which it is discharged outside of the motor room. If desired the heated air may be passed through cooling and cleaning equipment and blown back into the motor room.

It will be seen, therefore, that a relatively simple construction has been provided which furnishes very eiective cooling for the machine and which makes it possible to discharge the heated air outside of the motor room, thus avoiding un'- desirably high temperatures in the room. It is to be understood that, while the invention has been shown as applied to a direct current machine for the purpose of illustration, it is not limited to such machines but may equally well be applied to alternating current machines of any type.

Although a specific embodiment of the invention has been shown and described, it is to be understood that the invention is not limited to the particular details of construction shown, butVin its broadest aspect, it includes all equivalent embodiments and modications which come within the scope of the appended claims.

I claim as my invention:

l. A dynamoelectric machine comprising two aligned stator members, a shaft, two rotor members on the shaft cooperating respectively with the stator members, a -cover between the stator members and secured to them, said cover completely enclosing the space between the stator ,bers on the shaft cooperating respectively with 'the stator members, a cover between the stator members and secured to them, said cover completely enclosing the space between the stator members and having two openings therein, an

f air inlet duct extending through one of said .openings into the interior of the cover, said duct being closed at its end and having openings on each side concentric with the shaft and of approximately the same diameter as the rotor members and an external air outlet duct conybers comprising means for enclosing the space between the stator members, an air duct extending into said space, said duct being open at its outer end for the entrance of air from a room in which the machine is located and closed at its inner end and having openings within said space opposite the rotor members'and of approximately the same diameter as the rotor members, and a second air duct communicating with said space for the discharge of heated air therefrom and extending outside the room.

4. A Ventilating system for a dynamoelectric machine having two stator members, a shaft and two rotor members mounted on the shaft and cooperating respectively with the ,stator members comprising means for enclosing the spa-ce between the stator members, an air duct extending into said space, said duct being open at its outer end for the entrance of air from a room. in which the machine is located and closed at its inner end and having openings within said space opposite the rotor members and of approximately the same diameter as the rotor members,

a second air duct communicating with said space for the discharge of heated air therefrom and extending outside the room, and end bells enclosing the outer sides of the stator members and having central openings to permit the entrance of air for cooling the stator windings.

5. A dynamoelectric machine comprising two aligned stator members, a shaft, two rotor members on the shaft cooperating respectively with the stator members, a cover between the stator members and secured to them, said cover cornpletely enclosing the space between the stator members and having two openings therein, an air inlet duct extending through one of said openings, said duct being closed at its end and having openings in its sides opposite the rotor members, and of approximately the same diameter as the rotor members, an external air outlet duct connected to the other opening, and end bells on the outer sides of the stator members, said end bells having central openings of greater iameter than the rotor members.

6. A dynamoelectric machine comprising two aligned stator members, a shaft, two rotor members `on the shaft cooperating respectively with the stator members, a cover between the stator members and secured to them, said cover completely enclosing the space between the stator members and having two openings therein, an air inlet duct extending through one of said openings into the interior of the cover, said duct being closed at its end and having openings on v each side concentric with the shaft and' of approximately the same diameter es they rotor members, an external air outlet duct connected to the other opening in the cover, and end bells on the outer sidesof the stator members, said end bells having central openings of great enough diameter to permit the entrance of air for cooling the stator windings.

HAROLD E. STOKES. 

